Gallagher Holdings, a metals firm owned by Russian oligarch Alisher Usmanov, has launched a takeover bid for Irish property developer Abbey.Usmanov's firm upped its shareholding in Abbey from 47.2% to 51.6% on Wednesday, triggering a mandatory offer for the firm under Irish Takeover Rules.The rules say Gallagher must offer the highest price it has paid for Abbey shares over the last 12 months."The offer will be 530 pence in cash for each Abbey Share, valuing the entire issued ordinary share capital of Abbey at approximately £114.1m," Gallagher's statement said.It added that the mandatory offer was unconditional and a final offer which would not be increased. Abbey responded saying: "The independent directors of Abbey, being all of the directors of Abbey other than Messrs. Charles and David Gallagher ("Independent Directors"), will consider the mandatory offer and will provide further advice to shareholders in due course""In the meantime, Abbey shareholders should take no action," Abbey said.In July Abbey reported profits were up for the 12 months to the end of April but warned margins would remain under pressure. Profits before tax for the full year were €12.1m against €11.5m in the previous year. After a tax charge of €3.2m the group made a profit of €8.9m reflecting earnings per share of 39.94 cents.